MapLight Therapeutics Announces Completion of Enrollment in ZEPHYR Phase 2 Trial and Updates Expected Timing of Topline Results

MapLight Therapeutics (NASDAQ: MPLT) completed enrollment in its Phase 2 ZEPHYR trial for ML-007C-MA in schizophrenia and completed the final patient visit in its Phase 2 IRIS trial for ML-004 in autism spectrum disorder.

Rhea-AI Summary

MapLight Therapeutics (NASDAQ: MPLT) completed enrollment in its Phase 2 ZEPHYR trial for ML-007C-MA in schizophrenia and completed the final patient visit in its Phase 2 IRIS trial for ML-004 in autism spectrum disorder. ZEPHYR randomized 307 participants 1:1:1; IRIS randomized 161 participants, including >100 adolescents aged 12–17. Primary endpoints are change in PANSS total score (ZEPHYR, Week 5) and change in ABI Social Communication score (IRIS, Week 12). Topline results for both trials are expected by mid‑August 2026.

Positive

• ZEPHYR enrollment completed: 307 participants randomized 1:1:1
• IRIS final patient visit completed; 161 participants randomized
• IRIS met adolescent enrollment target: >100 participants aged 12–17
• Topline results for both Phase 2 trials expected by mid‑August 2026

Negative

• Both programs are Phase 2; clinical efficacy remains unconfirmed until topline readouts
• Topline outcome uncertainty remains until results are reported by mid‑August 2026

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On May 1, the day this news came out, MPLT closed 3.67% below the previous close.

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Key Figures

ZEPHYR participants: 307 participants ZEPHYR dosing arm: ML-007C-MA 210/3 mg BID ZEPHYR dosing arm: ML-007C-MA 330/6 mg QD +5 more

ZEPHYR participants

307 participants

Phase 2 schizophrenia trial randomized population

ZEPHYR dosing arm

ML-007C-MA 210/3 mg BID

One active dose group in Phase 2 ZEPHYR

ZEPHYR dosing arm

ML-007C-MA 330/6 mg QD

Second active dose group in Phase 2 ZEPHYR

ZEPHYR primary endpoint

PANSS total change to Week 5

Primary efficacy endpoint in schizophrenia trial

IRIS participants

161 participants

Phase 2 autism spectrum disorder trial randomized population

IRIS adolescent age range

Aged 12–17

Adolescent cohort in autism spectrum disorder trial

IRIS primary endpoint

ABI-Social Communication change to Week 12

Primary efficacy endpoint in IRIS trial

Topline timing

By mid-August 2026

Expected topline results for both Phase 2 trials

Previous Clinical trial Reports

2 past events · Latest: Jan 09

Same Type 2 events

1. Jan 09

   Clinical timing update

   24h Move

   +4.8%

   Narrowed Q3 2026 timing for topline results in two Phase 2 trials.

2. Jan 05

   Regulatory designation

   24h Move

   +2.7%

   FDA Fast Track designation and plans for a 300‑patient Phase 2 VISTA study.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

randomized, double-blind, placebo-controlled, panss, cgi-s, autism behavioral inventory (abi), +2 more

6 terms

randomized, double-blind, placebo-controlled medical

"The Phase 2 ZEPHYR trial is a randomized, double-blind, placebo-controlled trial..."

A "randomized, double-blind, placebo-controlled" process is a method used to test the effectiveness of a new treatment or intervention. Participants are randomly assigned to different groups, with one receiving the real treatment and the other a fake version, called a placebo. Neither the participants nor the researchers know who is receiving which, which helps ensure unbiased results. For investors, this rigorous approach increases confidence that the findings are accurate and not influenced by guesswork or bias.

panss medical

"Primary endpoint is the change in PANSS total score from baseline to Week 5"

A PANSS is a standardized clinical rating scale used in psychiatry to measure the severity of symptoms in disorders like schizophrenia, scoring both “positive” signs (added symptoms such as hallucinations or delusions) and “negative” signs (lost functions such as social withdrawal) plus general symptoms. Investors care because PANSS scores are a key way regulators and doctors judge whether a treatment meaningfully improves patients, so changes on this scale can determine a drug’s approval prospects, prescribing uptake, and commercial value — like a test score that helps predict market success.

cgi-s medical

"Key secondary endpoints include change in CGI-S score, PANSS-Marder positive..."

CGI-S (Clinical Global Impressions – Severity) is a simple, clinician-rated scale that scores how severe a patient’s illness is at a given time, usually on a 1–7 range where higher scores mean worse symptoms. Investors watch CGI-S in clinical trial reports because it gives a quick, standardized snapshot of whether a treatment produces meaningful clinical improvement—like a single thermometer reading that summarizes how much a patient’s condition has changed.

autism behavioral inventory (abi) medical

"Primary endpoint is the change in Autism Behavioral Inventory (ABI)-Social..."

A caregiver-completed questionnaire that tracks the severity and change of core autism symptoms and related behaviors over time, such as social interaction, communication, sleep, and repetitive actions. Investors watch ABI results like a thermometer for a clinical program—consistent improvement can signal a treatment’s effectiveness, support regulatory approval, and affect a drug’s commercial prospects, while little or no change may raise doubts about a therapy’s value.

cgi-i medical

"Key secondary endpoints include change in CGI-I, ABI-C and Aberrant Behavior..."

A CGI‑I (Clinical Global Impression–Improvement) score is a simple clinician judgment that rates how much a patient's overall condition has changed after treatment, typically on a scale from 'very much improved' to 'very much worse.' Investors watch CGI‑I results because they offer a quick, real-world snapshot of a therapy's effectiveness beyond lab tests or questionnaires, like a doctor's one‑line progress report that helps gauge a drug's potential market value and regulatory prospects.

aberrant behavior checklist-irritability (abc-i) medical

"Key secondary endpoints include change in CGI-I, ABI-C and Aberrant Behavior Checklist-Irritability (ABC-I)..."

A caregiver‑completed questionnaire that measures irritability and related challenging behaviors in people with developmental or neuropsychiatric conditions. Think of it like a teacher’s checklist that scores how often and how severe outbursts, aggression, or self‑injury are; in clinical trials it serves as a standardized endpoint to show whether a drug reduces those behaviors, which can directly affect trial success, regulatory decisions, and commercial prospects.

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• Enrollment completed in ML-007C-MA’s ZEPHYR Phase 2 trial in schizophrenia
• Last patient visit completed for ML-004’s IRIS Phase 2 trial in autism spectrum disorder
• Topline results from both Phase 2 trials expected by mid-August 2026
  
  

SAN FRANCISCO and BOSTON, May 01, 2026 (GLOBE NEWSWIRE) -- MapLight Therapeutics, Inc. (Nasdaq: MPLT), a clinical-stage biopharmaceutical company focused on improving the lives of patients suffering from debilitating central nervous system disorders, today announced completion of enrollment in its Phase 2 ZEPHYR trial evaluating ML-007C-MA for the treatment of schizophrenia. The Company also announced completion of the final patient visit in its Phase 2 IRIS trial evaluating ML-004 for the treatment of autism spectrum disorder. The Company expects to report topline results from both Phase 2 trials by mid-August 2026.

"The robust enrollment in the ZEPHYR trial reflects the critical unmet need for new treatment options in schizophrenia," said Chris Kroeger, Co-Founder and Chief Executive Officer. "We are grateful for the enthusiasm and commitment of both participants and investigators that enabled efficient study conduct while maintaining high quality standards. 2026 is shaping up to be an important year for MapLight and we look forward to sharing the topline data from these trials."

The Phase 2 ZEPHYR trial is a randomized, double-blind, placebo-controlled trial evaluating the efficacy, safety, and tolerability of ML-007C-MA in inpatient adult participants with schizophrenia experiencing an acute exacerbation of psychosis.

• 307 participants in the trial were randomized 1:1:1 to receive either placebo, ML-007C-MA 210/3 mg twice daily, or ML-007C-MA 330/6 mg once daily
• Primary endpoint is the change in PANSS total score from baseline to Week 5
• Key secondary endpoints include change in CGI-S score, PANSS-Marder positive and negative factor scores from baseline to Week 5
• Exploratory endpoints include change in cognitive function, assessed across multiple domains commonly impacted in schizophrenia, from baseline to Week 5

The Phase 2 IRIS trial is a randomized, double-blind, placebo-controlled trial evaluating the efficacy, safety, and tolerability of ML-004 in adults and adolescents with autism spectrum disorder.

• 161 participants were randomized in the trial, consistent with our enrollment target of over 100 adolescents (aged 12-17)
• Primary endpoint is the change in Autism Behavioral Inventory (ABI)-Social Communication Domain Score from baseline to Week 12
• Key secondary endpoints include change in CGI-I, ABI-C and Aberrant Behavior Checklist-Irritability (ABC-I) score from baseline to Week 12
  
  

About MapLight Therapeutics

MapLight Therapeutics is a clinical-stage biopharmaceutical company focused on improving the lives of patients suffering from debilitating central nervous system disorders. The Company was founded by globally recognized leaders in psychiatry and neuroscience research to address the lack of circuit-specific pharmacotherapies available for patients. The Company’s discovery platform holds the potential to fill this void by identifying neural circuits causally linked to disease and targeting those circuits for therapeutic modulation.

For more information, please visit www.maplightrx.com.

Forward-Looking Statements

Certain statements in this press release may constitute “forward-looking statements” within the meaning of the federal securities laws, including the Company’s expectations regarding the potential benefits of its current and future product candidates and programs, and the anticipated timing of results from the Company’s Phase 2 ZEPHYR and Phase 2 IRIS clinical trials. Words such as “may,” “might,” “will,” “objective,” “intend,” “should,” “could,” “can,” “would,” “expect,” “believe,” “design,” “estimate,” “predict,” “potential,” “develop,” “plan” or the negative of these terms, and similar expressions, are intended to identify forward-looking statements. While the Company believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to the Company on the date of this release. These forward-looking statements are based upon current estimates and assumptions and are subject to various risks and uncertainties (including, without limitation, those set forth in the Company’s filings with the U.S. Securities and Exchange Commission (SEC)), many of which are beyond the Company’s control and subject to change. Actual results could be materially different. Risks and uncertainties include: global macroeconomic conditions and related volatility; expectations regarding the initiation, progress, and expected results of the Company’s preclinical studies, clinical trials and research and development programs; the unpredictable relationship between preclinical study results and clinical study results; the risk that results obtained in any clinical trials to date may not be indicative of results obtained in ongoing or future trials; the timing or likelihood of regulatory filings and approvals; expectations regarding the Company’s ability to fund its current operations; and other risks and uncertainties identified in the Company’s Annual Report on Form 10-K filed with the SEC on March 26, 2026, and subsequent disclosure documents the Company may file with the SEC. The Company claims the protection of the safe harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. The Company expressly disclaims any obligation to update or alter any statements whether as a result of new information, future events or otherwise, except as required by law.

For investor inquiries: investors@maplightrx.com

For media inquiries: media@maplightrx.com

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

When will MapLight (MPLT) report topline results for the ZEPHYR and IRIS Phase 2 trials?

MapLight expects to report topline results for both ZEPHYR and IRIS Phase 2 trials by mid‑August 2026. According to company, ZEPHYR randomized 307 participants and IRIS randomized 161 participants, including over 100 adolescents aged 12–17.

How many participants were randomized in MapLight's ZEPHYR Phase 2 trial (MPLT)?

The ZEPHYR Phase 2 trial randomized 307 adult participants 1:1:1 into placebo and two ML‑007C‑MA dose arms. Primary endpoint is change in PANSS total score to Week 5; secondary endpoints include CGI‑S and PANSS‑Marder factor scores.

What is the primary endpoint in the IRIS Phase 2 autism trial (MPLT)?

The IRIS trial's primary endpoint is change in ABI Social Communication Domain score from baseline to Week 12. According to company, 161 participants were randomized; key secondary endpoints include CGI‑I, ABI‑C, and ABC‑Irritability scores.

What doses of ML‑007C‑MA were tested in the ZEPHYR trial (MPLT)?

ZEPHYR tested ML‑007C‑MA at 210/3 mg twice daily and 330/6 mg once daily versus placebo. The trial was double‑blind, placebo‑controlled in inpatient adults with acute psychosis; safety, tolerability and efficacy were assessed to Week 5.

How many adolescents were included in MapLight's IRIS trial (MPLT)?

IRIS randomized a cohort that included over 100 adolescents aged 12–17, within a total of 161 participants. According to company, the adolescent enrollment target was met and the trial completed its final patient visit.